1. Field of the Invention
The present invention relates to a two component dentifrice composition, having a first component containing stannous fluoride and a second component containing potassium nitrate and more particularly to such a composition which exhibits lower astringency and enhanced taste.
2. The Prior Art
Incorporation of stannous compounds into oral health products for the purpose of achieving particular clinical benefits such as caries prevention, plaque control and the reduction of gingivitis is known in the art. In spite of these benefits, stannous compounds are not widely used in oral care formulations as stannous compounds react with water and other common oral care ingredients to form insoluble tin and other undesirable products. Further, stannous ions impart an astringent, bitter, sour metallic taste to dentifrices, which is not consumer acceptable and which is particularly unacceptable to children, astringency being defined as a drying of the oral mucosa, which results in a puckering or styptic sensation.
Copending U.S. patent application Ser. No. 08/287,371, filed Aug. 8, 1994, discloses a dual component dental desensitizing composition comprised of a stannous salt-containing anhydrous gel, and a potassium salt-containing aqueous dentifrice, which are admixed immediately prior to application to the teeth to avoid any appreciable formation of insoluble tin or reaction product of tin and hence providing less than the formulated quantity of tin salt, such as SnF.sub.2, and less than the formulated quantity of potassium salt, such as KNO.sub.3, to the oral surfaces. However, the composition retains the astringent, sour, metallic taste attributes associated with stannous compounds. Accordingly, there is a need in the art for a dental desensitizing composition containing tin salts, which does not have such negative attributes.